She wasn't wearing it when she left Guwahati that morning, boarding her flight in a Tory Burch dress.
Ms Middleton wore a red Alexander McQueen dress printed with paisleys as her first outfit in Mumbai on April 10. Ms Middleton laid a wreath at the memorial to those who died in the 26/11 attacks at the Taj Palace Hotel.
Kate Middleton then changed into a breezy Anita Dongre printed tunic to meet underprivileged children at the Oval Maidan, where she also played cricket with Sachin Tendulkar.
As her third outfit, Ms Middleton chose a blue Jenny Packham gown with beadwork made in India and Amrapali jewels. She was at a charity gala attended by Bollywood stars like Shah Rukh Khan and Aishwarya Rai Bachchan.
On April 11, Kate Middleton met young entrepreneurs and business leaders at Social Offline in Mumbai wearing a white dress by Emilia Wickstead.
After the event at Social Offline, the couple flew to New Delhi. In the evening, Ms Middleton wore a white and black patterned dress by Alice Temperly to a British High Commission-hosted party to celebrate Queen Elizabeth's birthday in New Delhi.
On the third day of her visit to India, Kate Middleton wore a green dress by Alice Temperley for lunch with Prime Minister Narendra Modi at New Delhi's Hyderabad House on April 12. Ms Middleton is currently touring India with Prince William.
Earlier, Kate Middleton visited an NGO which helps vulnerable street children who live at the New Delhi Railway Station. She looked pretty in a red printed dress.
On the fourth day of their India visit, Prince William and Kate Middleton were spotted in Assam's famous Kaziranga National Park. Ms Middleton kept her look casual in brown pants from Zara teamed with an R M Williams top for the safari on April 13. Very chic.
Assam is celebrating the festival of Bihu this week and included Will and Kate in the revelry. In a crowd of women dressed in beautiful traditional mekhla chador, Ms Middleton did her best in an Anna Sui maxi. (Image: AFP)
Kate Middleton also visited the Pan Bari village in Assam in a Topshop frock.